The human body uses a complex feedback loop to manage blood sugar. Blood glucose, insulin, the pancreas, the liver, and the cells all play important roles. If you have either Type 1 or Type 2 Diabetes straightening out each piece of this blood sugar puzzle can be really difficult! To make diabetes management even more challenging, this feedback loop behaves differently when you’re exercising.

Don’t get confused here—exercise is a wonderful thing for diabetics! But, all diabetics need to be aware of the effects that exercise has on their insulin and blood sugar levels. Any type of aerobic activity, from walking to swimming to cycling, will lower blood glucose levels during the exercise and can increase insulin sensitivity for up to 24 hours after you’re done with the activity. Without properly adjusting your insulin dose, exercise may lead to hypoglycemia.

Exercise, Insulin, and Glucose: How They Work Together

No diabetic wants to get into trouble with exercise-induced hypoglycemia and the best way to avoid it is to learn how your body uses glucose when you’re working out. The easiest place to start is in the muscles.

During exercise, your muscles use glucose as fuel. They do have some glucose in storage and that’s the fuel they use first. After the muscular glucose runs out, the pancreas releases the hormone glucagon. This triggers the liver to release glucose into the blood stream and that’s what the muscles will use for extended fuel.

Usually, the body of a diabetic has a difficult time getting glucose into the cells. However, during exercise, the muscle contractions stimulate the cells to easily pull in the glucose they need. Exercise also increases the effectiveness of the insulin in your blood. This is true even when the activity is over. The muscles want to replenish their stores of glucose, so they will continue to pull in extra glucose for hours.

All of these interactions mean that diabetics need to carefully manage their insulin dose and blood sugar levels before, during, and after exercise. If you have too much insulin in your bloodstream during exercise, the muscles will pull in too much blood glucose and you’ll become hypoglycemic. However, if you don’t have enough insulin, the glucose cannot get into the muscles and you may become hyperglycemic.

How to Adjust Your Insulin for Exercise

Now that you know what’s going on inside of your body during exercise, what should you do about it? All diabetics should lower their insulin dose before exercising, but the amount of that reduction is different for every individual. In general, you should reduce your insulin dose by one or two units. Here are a few factors to consider:

How fit are you?

If you haven’t exercised in a long time, you may be more likely to be hypoglycemic during activity.

How long and difficult is your activity?

Long, strenuous workouts are the most likely culprits of hypoglycemia.

What time of day is it?

Diabetics who exercise before breakfast usually have a lower chance of becoming hypoglycemic.

What are your blood glucose levels before you begin exercising?

If you skip a meal, you are more likely to have low blood sugar during exercise. If you’re blood sugar is above 180 mg/dL, you may not need any insulin adjustments.

Remember, you should check your blood sugar once every hour during exercise. If your level is below 70 mg/dL, stop the activity and take 15-20 grams of fast-acting carbohydrate. You can recheck your glucose levels after 15 minutes and return to exercising if the levels are within normal range.

Precautions

Remember, we are referring to aerobic, moderate-intensity exercise. If you are participating in particularly strenuous, anaerobic exercises, you will need to make different adjustments to your insulin doses.

It is very important that you speak with your doctor before you begin any new aerobic activities or exercise regimens. He or she can help you properly adjust your insulin dose and instruct you about the exercises that are best suited for your unique circumstances.

One of the most important things a diabetic can know is how their blood glucose levels can affect the other parts of the body. Even though the body is broken down into various systems, ie cardiac, respiratory, muscles, etc, they all work together and are affected by one another. Any disorder in the body, even if it is technically isolated to one part, can have effects on other systems. For example, someone with a respiratory disorder has trouble bringing in oxygen. This can make the heart work harder to get oxygen to the rest of the body.

Due to the set up of the human body, diabetes can actually cause high cholesterol levels, especially if blood glucose levels are not controlled. The various chemicals (hormones) that are secreted by the pancreas have control over cholesterol levels and blood sugars. Here, we will explain how the pancreas works, and how the effects of diabetes can prevent the body from being able to control your cholesterol levels and vice versa.

The Role of the Pancreas

The association of high cholesterol and diabetes is because the pancreas has the ability to control both in many situations. However, the effects diabetes has on the pancreas can actually prevent the body from properly managing cholesterol.

When you eat, the pancreas secretes several different chemicals. These chemicals are pushed into the digestive system and others into the blood stream to help break down various parts of your meal. This will answer a lot of questions about diabetes, and also make you aware of other problems you could encounter while trying to get your blood glucose levels under control.

The first set of chemicals that are secreted are Trypsin and chymotrypsin, which are essentially fancy names for chemicals that break down the proteins found in meats, beans, cheese, and lentils.

The second chemical that is secreted is Amylase, it is sent to break carbohydrates down into usable energy.

The third chemical that is secreted is Lipase, it is used to break down fats into useable and unusable parts, fatty acids and cholesterol.

The relation that this has to diabetes is due to other hormones that are created in the pancreas, these go straight into the blood stream. Insulin is created and released into the blood stream when the body senses that the blood sugar is too high, and to counteract low blood sugar it releases glucogen.

Diabetics do not create enough insulin in their pancreas to properly manage blood sugar. Damage to the pancreas that is caused by diabetes can also limit the amount of lipase that is produced. This can cause cholesterol to build up faster than it typically would.

The Relation between Diabetes and High Cholesterol

Because the body is focused on trying to create insulin that it cannot, the pancreas does not have all of the intended focus on breaking down fatty acids and cholesterol, which allows more of it to slip into the blood stream through the intestines. This means that diabetics are at a higher risk for developing high cholesterol especially if their blood sugars are not controlled.

Because the body is preoccupied, it doesn’t have time to sort out good cholesterol (HDL) from good cholesterol (LDL). Studies have shown that people with diabetes have up to a 40% increase in LDL levels which is essentially the basis of high cholesterol.